For simplification of the control and the programming of power supply devices, the so called power system management bus (PMBus) standard was defined. Known bus protocols, e.g., I2C or SMBus, allow the programming of a power management device by directly writing to internal registers of the device. Users interactively configuring such devices or writing software for power supply system host controllers need a lot of proprietary information about this devices as well as a deep insight knowledge on the function of their registers. For instance, the above mentioned known power system management bus standard PMBus provides a simple command language with standardized configuration and interaction commands. Thus, the user can concentrate more on the power system management concept itself and becomes more independent from the internal device architecture.
The programmability of a power supply device is usually handled by an integrated circuit. This integrated circuit can be programmed during different stages of manufacturing or preparation. These stages of manufacturing can be, for example, at the chip manufacturer, the module manufacturer, the system manufacturer, and the end-user. During each stage certain restrictions should apply to the programmability to ensure safe operation of the power supply device on the one hand and to allow sufficient flexibility of the power supply device on the other hand. These restrictions can be different at each stage and should be defined by the previous stage.